package com.colin.collection;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * @author colin
 * @create 2022-05-17 08:24
 */
public class HashMapDemo {

    public static void main(String[] args) {

        HashMap hashMap = new HashMap();
        hashMap.put("name","colin");

        ConcurrentHashMap<Object, Object> concurrentHashMap = new ConcurrentHashMap<>();
        concurrentHashMap.put("name","mark");

        CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
        list.add("colin");
    }
}
